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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Tuning the thermoelectric properties of metallo-porphyrins
AU - Al-Galiby, Qusiy
AU - Sadeghi, Hatef
AU - Algharagholy, Laith
AU - Grace, Iain Mark
AU - Lambert, Colin John
PY - 2016/1/28
Y1 - 2016/1/28
N2 - We investigated the thermoelectric properties of metalloporphyrins connected by thiol anchor groups to gold electrodes. By varying the transition metal-centre over the family Mn, Co, Ni, Cu, Fe, and Zn we are able to tune the molecular energy levels relative to the Fermi energy of the electrodes. The resulting single-molecule room-temperature thermopowers range from almost zero for Co and Cu centres, to +80 μV K−1 and +230 μV K−1 for Ni and Zn respectively. In contrast, the thermopowers with Mn(II) or Fe(II) metal centres are negative and lie in the range −280 to −260 μV K−1. Complexing these with a counter anion to form Fe(III) and Mn(III) changes both the sign and magnitude of their thermopowers to +218 and +95 respectively. The room-temperature power factors of Mn(II), Mn(III), Fe(III), Zn and Fe(II) porphyrins are predicted to be 5.9 × 10−5 W m−1 K−2, 5.4 × 10−4 W m−1 K−2, 9.5 × 10−4 W m−1 K−2, 1.6 × 10−4 W m−1 K−2 and 2.3 × 10−4 W m−1 K−2 respectively, which makes these attractive materials for molecular-scale thermoelectric devices.
AB - We investigated the thermoelectric properties of metalloporphyrins connected by thiol anchor groups to gold electrodes. By varying the transition metal-centre over the family Mn, Co, Ni, Cu, Fe, and Zn we are able to tune the molecular energy levels relative to the Fermi energy of the electrodes. The resulting single-molecule room-temperature thermopowers range from almost zero for Co and Cu centres, to +80 μV K−1 and +230 μV K−1 for Ni and Zn respectively. In contrast, the thermopowers with Mn(II) or Fe(II) metal centres are negative and lie in the range −280 to −260 μV K−1. Complexing these with a counter anion to form Fe(III) and Mn(III) changes both the sign and magnitude of their thermopowers to +218 and +95 respectively. The room-temperature power factors of Mn(II), Mn(III), Fe(III), Zn and Fe(II) porphyrins are predicted to be 5.9 × 10−5 W m−1 K−2, 5.4 × 10−4 W m−1 K−2, 9.5 × 10−4 W m−1 K−2, 1.6 × 10−4 W m−1 K−2 and 2.3 × 10−4 W m−1 K−2 respectively, which makes these attractive materials for molecular-scale thermoelectric devices.
U2 - 10.1039/C5NR06966A
DO - 10.1039/C5NR06966A
M3 - Journal article
VL - 2016
SP - 2428
EP - 2433
JO - Nanoscale
JF - Nanoscale
SN - 2040-3364
IS - 4
ER -